The Alaska class consisted of six cruisers ordered before World War II for the United States Navy. They were officially classed as large cruisers (CB), but others have regarded them as battlecruisers. They were all named after territories or insular areas of the United States, signifying their intermediate status between larger battleships and smaller heavy and lighter cruisers.[C] Of the six planned, two were completed, the third's construction was suspended on 16 April 1947, and the last three were canceled. Alaska and Guam served with the U.S. Navy for the last year of World War II as bombardment ships and fast carrier escorts. They were decommissioned in 1947 after spending only 32 and 29 months in service, respectively.

The idea for a large cruiser class originated in the early 1930s when the U.S. Navy sought to counter Deutschland-class "pocket battleships" being launched by Germany. Planning for ships that eventually evolved into the Alaska class began in the late 1930s after the deployment of Germany's Scharnhorst-class battleships and rumors that Japan was constructing a new battlecruiser class.[7][D] To serve as "cruiser-killers" capable of seeking out and destroying these post-Treaty heavy cruisers, the class was given large guns of a new and expensive design, limited armor protection against 12-inch shells, and machinery capable of speeds of about 31–33 knots (36–38 mph, 58–61 km/h).

Heavy cruiser development steadied between World War I and World War II thanks to the terms of the Washington Naval Treaty and successor treaties and conferences, where the United States, Britain, Japan, France, and Italy agreed to limit heavy cruisers to 10,000 tons displacement with 8-inch main armament. Up until the Alaska class, US cruisers designed between the wars followed this pattern.[12]

The initial impetus for the Alaska design came from the deployments of Germany's so-called pocket battleships in the early 1930s. Though no actions were immediately taken, these thoughts were revived in the late 1930s when intelligence reports indicated Japan was planning or building "super cruisers" that would be much more powerful than the current US heavy cruisers.[3][6][11][13][E] The navy responded in 1938 when the General Board asked the Bureau of Construction and Repair to conduct a "comprehensive study of all types of naval vessels for consideration for a new and expanded building program".[14] The US President at the time, Franklin Delano Roosevelt, may have taken a lead role in the development of the class with his desire to have a counter to raiding abilities of Japanese cruisers and German pocket battleships.[15] While these claims are difficult to verify,[6][16] they have led to the speculation that their design was "politically motivated".[17] These were the most powerful cruisers ever built.

One historian described the design process of the Alaska class as "torturous" due to the numerous changes and modifications made to the ship's layouts by numerous departments and individuals.[7] Indeed, there were at least nine different layouts,[18] ranging from 6,000-ton Atlanta-class anti-aircraft cruisers[19] to "overgrown" heavy cruisers[7] and a 38,000-ton mini-battleship that would have been armed with twelve 12-inch and sixteen 5-inch guns.[19] The General Board, in an attempt to keep the displacement under 25,000 tons, allowed the designs to offer only limited underwater protection. As a result, the Alaska class, when built, were vulnerable to torpedoes and shells that fell short of the ship.[20] The final design was a scaled-up Baltimore class that had the same machinery as the Essex-classaircraft carriers. This ship combined a main armament of nine 12-inch guns with protection against 10-inch gunfire into a hull that was capable of 33 knots (61 km/h; 38 mph).[13]

The Alaskas were officially funded in September 1940 along with a plethora of other ships as a part of the Two-Ocean Navy Act.[11][21][F] Their role had been altered slightly: in addition to their surface-to-surface role, they were planned to protect carrier groups. Because of their bigger guns, greater size and increased speed, they would be more valuable in this role than heavy cruisers, and would provide insurance against reports that Japan was building super cruisers more powerful than U.S. heavy cruisers.[11]

A conversion of the Alaska cruisers to carriers was "particularly attractive"[22] because of the many similarities between the design of the Essex-class aircraft carriers and the Alaska class, including the same machinery.[23] However, when Alaska cruisers were compared to the Essex carriers, converted cruisers would have had a shorter flight deck (so they could carry only 90% of the aircraft),[22] would have been 11 feet (3.4 m) lower in the water, and could travel 8,000 nautical miles (15,000 km) less at 15 knots (28 km/h; 17 mph). In addition, the large cruiser design did not include the massive underwater protections found in normal carriers due to the armor weight devoted to counter shell fire. Lastly, an Alaska conversion could not satisfy the navy's goal of having new aircraft carriers quickly, as the work needed to modify the ships into carriers would entail long delays. With this in mind, all planning to convert the Alaskas was abandoned on 7 January 1942.[24]

Of the six Alaska-class cruisers that were planned, only three were laid down. The first two, Alaska and Guam, were completed. Construction of Hawaii, the third, was suspended on 16 April 1947 when she was 84% complete.[3][14] The last three, Philippines, Puerto Rico, and Samoa, were delayed since all available materials and slipways were allocated to higher priority ships, such as aircraft carriers, destroyers, and submarines. Construction had still not begun when steel shortages[25] and a realization that these "cruiser-killers" had no more cruisers to hunt—as the fleets of Japanese cruisers had already been defeated by aircraft and submarines—made the ships "white elephants".[6] As a result, construction of the last three members of the class never began, and they were officially canceled on 24 June 1943.[26][27][28]

Alaska and Guam served with the U.S. Navy during the last year of World War II. Similar to the Iowa-classfast battleships, their speed made them useful as shore bombardment ships and fast carrier escorts. Both protected Franklin when she was on her way to be repaired in Guam after being hit by two Japanese bombs. Afterward, Alaska supported the landings on Okinawa, while Guam went to San Pedro Bay to become the leader of a new task force, Cruiser Task Force 95. Guam, joined by Alaska, four light cruisers, and nine destroyers, led the task force into the East China and Yellow Seas to conduct raids upon shipping; however, they only encountered Chinese junks.[1][2] By the end of the war, the two had become celebrated within the fleet as excellent carrier escorts.[8] During the war, both ships were part of Cruiser Division 16 commanded by Rear Admiral Francis S. Low, USN.[29][30][31]

After the war, both ships served as part of Task Force 71, the designation for the U.S. Seventh Fleet's North China Naval Force. Its mission was to support the allied occupation of the Korean peninsula.[32][33] This included executing various show-the-flag operations along the western coast of Korea as well as in the Gulf of Chihli. These naval demonstrations preceded Operation Campus, the amphibious landing of U.S. Army ground forces at Jinsen, Korea, on 8 September 1945.[34][35] Subsequently, both ships returned to the United States in mid-December 1945, and they were decommissioned and "mothballed" in 1947.[1][2] after having spent 32 months (Alaska) and 29 months (Guam) in service.[19]

In 1958, the Bureau of Ships prepared two feasibility studies to explore whether Alaska and Guam could be suitably converted into guided-missile cruisers. The first study involved removing all of the guns in favor of four different missile systems. At $160 million, the cost of this proposed removal was seen as prohibitive, so a second study was initiated. The study left the forward batteries (the two 12-inch triple turrets and three of the 5-inch dual turrets) unchanged, and added a reduced version of the first plan on the stern of the ship. Even though the proposals would have cost approximately half as much as the first study's plan ($82 million), it was still seen as too expensive.[36] As a result, both ships were stricken from the Naval Vessel Register on 1 June 1960. Alaska was sold for scrap on 30 June 1960, and Guam on 24 May 1961.[1][2]

The still-incomplete Hawaii was considered for a conversion to be the Navy's first guided-missile cruiser;[G] this thought lasted until 26 February 1952, when a different conversion to a "large command ship" was contemplated. In anticipation of the conversion, her classification was changed to CBC-1. This would have made her a "larger sister" to Northampton,[6] but a year and a half later (9 October 1954) she was re-designated CB-3. Hawaii was stricken from the Naval Vessel Register on 9 June 1958 and was sold for scrap in 1959.[3]

The Iowa-class battleship Missouri (top) and Alaska moored at the same pier, showing their difference in size

Early in its development, the class used the US battlecruiserdesignation CC, which had been planned for the Lexington class. However, the designation was changed to CB to reflect their new status, "large cruiser", and the practice of referring to them as battlecruisers was officially discouraged.[16] The U.S. Navy then named the individual vessels after U.S. territories, rather than states (as was the tradition with battleships) or cities (for which cruisers were named), to symbolize the belief that these ships were supposed to play an intermediate role between heavy cruisers and fully-fledged battlecruisers.[7]

The Alaska class certainly resembled contemporary US battleships (particularly the North Carolina class, South Dakota class, and Iowa class) in appearance, including the familiar 2-A-1 main battery and massive columnar mast, and displaced twice that of the newest heavy cruisers (the Baltimore class).[37] In weight, the ships were only 5,000 tons less than the London Treaty battleship standard displacement limit of 35,000 long tons (36,000 t), also longer than several treaty battleships such as the King George V and North Carolina-classes.

In design and armor the Alaska class are regarded as "large cruisers" rather than battlecruisers. Their design was scaled up from the treaty cruisers limited by the Washington, London and Second London naval treaties.[6] In common with U.S. heavy cruisers, they had aircraft hangars and a single large rudder. Their armor lacked the underwater protection systems found on full-fledged battleships and even intermediate capital ships like the French Dunkerque and German Scharnhorst classes. This left the Alaskas virtually defenseless against torpedoes, as well as vulnerable to shells falling slightly short and continuing underwater to hit the hull.[7] While the Alaskas had more side armor than other contemporary U.S. cruisers, their protection was only marginally capable of stopping 12" fire;[38] they were vulnerable to battleship fire (14–16" fire) at any range.[39]

In addition, despite being much larger than the Baltimore class, the numbers of secondary and anti-aircraft batteries of the Alaskas were similar. Whereas the Alaska class carried twelve 5"/38 caliber in six twin turrets, fifty-six 40 mm, and thirty-four 20 mm guns, the Baltimore class carried the same number of 5"/38s, eight fewer 40 mm, and ten fewer 20 mm.,[6] considerably fewer than new U.S. battleships that had ten (save for South Dakota (BB-57)) 5"/38 twin mounts while older refitted U.S. battleships had eight. Author Richard Worth remarked that when they were finally completed, launched, and commissioned, they had the "size of a battleship but the capabilities of a cruiser". The Alaska class was similarly expensive to build and maintain as contemporary battleships yet far less capable due to armor deficiencies, while only able to put up an anti-aircraft defense comparable to the much cheaper Baltimore cruisers.[7]

Despite these cruiser-like characteristics, and the U.S. Navy's insistence on their status as cruisers, the Alaska class has been frequently described as battlecruisers.[37] The official navy magazine All Hands said "The Guam and her sister ship Alaska are the first American battle cruisers ever to be completed as such."[40] Some modern historians take the view that this is a more accurate designation because they believe that the ships were "in all senses of the word, battlecruisers", with all the vulnerabilities of the type.[9][41] The traditional Anglo-American battlecruiser concept had always sacrificed protection for the sake of speed and armament—they were not intended to stand up against the guns they themselves carried.[42] The Alaska's percentage of armor tonnage, 28.4%, was slightly less than that of fast battleships; the British King George V-class, the American Iowa class, and the battlecruiser/fast battleship HMS Hood all had armor percentages between 32 and 33%, whereas the Lexington-class battlecruiser design had a nearly identical armor percentage of 28.5%. In fact, older battlecruisers, such as the Invincible (19.9%), had a significantly lower percentage.[43] Armament-wise, they had much larger guns than contemporary heavy cruisers; while the Baltimore class only carried nine 8"/55 caliber Marks 12 and 15 guns,[44] the Alaska class carried nine 12"/50 caliber guns that were as good as, if not superior to, the old 14"/50 caliber gun used on the U.S. Navy's pre-treaty battleships.[45]

Guam firing her main battery during a training session sometime in 1944–1945.

As built, the Alaska class had nine 12"/50 caliber Mark 8 guns mounted in three triple (3-gun) turrets,[45] with two turrets forward and one aft, a configuration known as "2-A-1". The previous 12" gun manufactured for the U.S. Navy was the Mark 7 version, which had been designed for and installed in the 1912 Wyoming-class battleships. The Mark 8 was of considerably higher quality; in fact, it "was by far the most powerful weapon of its caliber ever placed in service."[46] Designed in 1939, it weighed 121,856 pounds (55,273 kg), including the breech, and could sustain an average rate of fire of 2.4–3 rounds a minute. It could throw a 1,140 pounds (520 kg) Mark 18 armor-piercing shell 38,573 yards (35,271 m) at an elevation of 45°, and had a 344-shot barrel life[45] (about 54 more than the much larger but similar 16"/50 caliber Mark 7 gun found in the Iowa battleships.).[47]

The turrets were very similar to those of the Iowa-class battleships, but differed in several ways; for example, the Alaska class had a two-stage powder hoist instead of the Iowa class's one-stage hoist. These differences made operating the guns safer and increased the rate of fire. In addition, a "projectile rammer" was added to Alaska and Guam. This machine transferred shells from storage on the ship to the rotating ring that fed the guns. However, this feature proved unsatisfactory, and it was not planned for Hawaii or any subsequent ships.[45]These cruisers had the heaviest guns of any cruiser of world war 2

Because Alaska and Guam were the only two ships to mount these guns, only ten turrets were made during the war (three for each ship including Hawaii and one spare). They cost $1,550,000 each and were the most expensive heavy guns purchased by the U.S. Navy in World War II.[16]

The secondary battery of the Alaska class was composed of twelve dual-purpose (anti-air and anti-ship) 5"/38 caliber guns in twin mounts, with four offset on each side of the superstructure (two on each beam) and two centerline turrets fore and aft. The 5"/38 was originally intended for use on only destroyers built in the 1930s, but by 1934 and into World War II it was being installed on almost all of the U.S.'s major warships, including aircraft carriers, battleships, and heavy and light cruisers.[48]

Arguably the most efficient light anti-aircraft gun of World War II, the 40 mm Bofors was used on nearly every major warship in the U.S. and UK fleets during World War II from about 1943 to 1945. Although they were a descendant of German and Swedish designs, the Bofors mounts used by the United States Navy during World War II had been heavily "Americanized" to U.S. Navy standards. This new standard resulted in a gun system set to English standards (now known as the Standard System) with interchangeable ammunition, simplifying the logistics situation for World War II. When coupled with hydraulic couple drives to reduce salt contamination and the Mark 51 director for improved accuracy, the 40 mm Bofors became a fearsome adversary, accounting for roughly half of all Japanese aircraft shot down between 1 October 1944 and 1 February 1945.[51]

The Oerlikon20 mm anti-aircraft gun was one of the most extensively used anti-aircraft guns of World War II; the U.S. alone manufactured a total of 124,735 of these guns. When activated in 1941, they replaced the 0.50" M2 Browning machine gun on a one-for-one basis. The Oerlikon gun remained the primary anti-aircraft weapon of the United States Navy until the introduction of the 40 mm Bofors in 1943.[52]

USS Alaska (CB-1) was commissioned on 17 June 1944. She served in the Pacific, screening aircraft carriers, providing shore bombardment at Okinawa, and going on raiding missions in the East China Sea. She was decommissioned on 17 February 1947 after less than three years of service and was scrapped in 1960.[1]

USS Guam (CB-2) was commissioned on 17 September 1944. She served in the Pacific with Alaska on almost all of the same operations. Along with Alaska, she was decommissioned on 17 February 1947 and was scrapped in 1961.[2]

USS Hawaii (CB-3) was intended as a third ship of the class, but she was never completed. Numerous plans to utilize her as a guided-missile cruiser or a large command ship in the years after the war were fruitless, and she was scrapped.[3]

USS Philippines (CB-4), Puerto Rico (CB-5), and Samoa (CB-6) were planned as the fourth, fifth, and sixth ships of the class, respectively. All were going to be built at Camden, New Jersey, but they were canceled before construction could begin.[26][27][28]

^Jane's thought that this mythical battlecruiser, the notional Chichibu class, would have six 12-inch guns and 30 knots (56 km/h; 35 mph) speed packed into a 15,000-ton ship. See Fitzsimons, Volume 1, 58 and Worth, 305.

^Japan actually developed plans for two super cruisers in 1941, though it was mostly in response to the new Alaska ships. However, the ships were not ordered due to the greater need for carriers. See Design B-65 cruiser.

^A similar proposal was made to convert the uncompleted Iowa-class battleship USS Kentucky (BB-66) into the first guided-missile battleship, but as with the proposal for Hawaii this conversion never materialized, and Kentucky was scrapped in 1958.